The download is SBuilderFS9.zip. It can then be unzipped to anywhere on your computer and run from the resulting SBuilderFS9 folder. Before running, you must have FS2004 installed on your computer. The initial run will take a few minutes, as SBuilder copies the needed textures from your default FS2004 install.

That should do it. Remember to register SBuilder... it's free for non-commercial usage. A free password, courtesy of Luis Sá has been included... just cut and paste it from the "FreePersonalPassword.txt" file.